1. Field of the Invention
This invention relates to new and useful improvements in machines for degerming webs of packing foil. More particularly, the invention relates to means for generating UV-rays along or within which is advanced the web of packing foil discharged from a supply reel for sterilizing purposes to be then fed to a packing machine for further processing thereof while keeping the same sterile, with the term "processing" conveying, for example, molding, loading, closing and separating packings from a strip of packing foil.
2. Description of the Prior Art
The use of UV-radiators for germ reduction also in webs of packing foil corresponding exposed, sterilized and advanced in a so-called disinfecting tube to be subsequently passed through molding, loading and sealing stations of a packing machine, are generally known in the art.
Conventional UV-based degermers for webs of packing foil operate on so-called radiator cassettes linearly arranged along the strip of packing foil, wherein the rear side of the housing accommodating the UV-radiator, for achieving enhanced ray utilization, must be silvered and of a reflector-type design. To insure the required degree of exposure, in addition, either special cassettes of a great width or length are employed or a plurality of smaller-sized cassettes are to be successively arranged along the conveyor track of the web of packing foil equally involving large space-requirements. In view of the operating life of UV-radiators which is limited, as a rule, to about 2000 hours, high replacement costs are involved, in addition, especially high costs are incurred by assembly, maintenance and cleaning operations as well as by the stoppage times involved.
Conventional UV-radiators, in addition, result in considerable ozone generation and, beyond that are likely to have a negative influence on the packing material (pollutant migration).
Water-cooled radiator systems that are also known in the art tend to form condensate once the dew point is fallen below which is likely to result in a direct reduction of the UV-exposure of the packings and also in an indirect reduction of exposure as a consequence of corrosive effects on the reflector faces.